THE USE OF STABLE CARBON ISOTOPE ANALYSIS FOR DETERMINING THE DIETARY HABITS OF THE FLORIDA MANATEE, TRICHECHUS MANATUS LATIROSTRIS

Abstract

AbstractThe sloughed skin from three captive manatees at Lowry Park Zoological Garden (Tampa, Florida) was examined over a period of one year to determine its stable carbon isotopic composition (δ13C). The food consumed by these manatees in a controlled diet was also sampled and its δ13C values determined. The sloughed skin δ13C values from the captive manatees were enriched by an average of +4.1%0 relative to lettuce (generally >98% of the diet) the animals consumed. δ13C values of the skin were shown to be related to changes in δ13C values of the lettuce.The stable carbon isotopic composition of internal tissues (liver, kidney, and blubber) and skin from dead, stranded manatees was also determined. These values were compared to values of vegetation that manatees are known to eat in the wild. The δ13C values of the internal tissues and skin of wild manatees were consistent with the range of δ13C values of their expected diet.